But buried inside was a remarkable factoid: While overall social sentiment was positive -- chatter on Facebook (FB) and Twitter was optimistic -- direct social shopper referrals dropped steeply.

"Shoppers referred from social networks such as Facebook, Twitter, LinkedIn (LNKD) and YouTube generated 0.34% of all online sales on Black Friday," the intro to the IBM report said, "a decrease of more than 35% from 2011."

And Twitter referrals -- not sales, but the actual inbound clicks from Twitter -- dropped from 0.02% last year to 0.00%. That's no typo. That's a zero -- almost incomprehensible for a service with roughly 500 million users.

Not surprisingly, the IBM report set off a social media food fight.

"Considering the massive flood of tweets, Facebook likes, and Bit.ly clicks that all of us at DataSift saw ," wrote Rob Bailey , chief executive of this U.K.-based social media data mining firm, "I was surprised by IBM's findings and think they may have given marketers the very wrong impression that social traffic wasn't important for retailers."

Twitter itself seemed to question IBM's results. Shane Steele, Twitter's director of sales and marketing, made a point of not commenting on the study to DestinationCRM.com, the New York-based industry market news service that covered the report.

To find out, let's pop open the hood on this baby and see what IBM has going on.

Looking at the reports It's no knock to say reports such as this are usually all about marketing. And sure enough this report pushes something called the IBM Digital Analytics Benchmark tool -- IBM's "Big Data" analysis service. In fact there is a link at the end of the report for the product, which the company says "measures every interaction on every participating site, capturing comprehensive customer and user behavioral data."

In other words, it's just counting what it sees: page views, sales, paid search sessions, marketing sessions, direct load sessions, all that stuff. And more, actually. From this show-all-the-data perspective, the report makes real -- and sobering -- sense.

In terms of good news, the overall sales seen on Page 6 render a dead-on accurate picture of holiday turnover: A solid shopping day on Thursday. A record spike on Black Friday. Some categories grew well. Department stores and home goods categories had a healthy 60% and 15% jumps in order value, respectively.